What Powder for 308?
- Thread starter Brux
- Start date
When I shot 168 SMK's 8208 worked very well. Switched to 175"s and Varget, good results. The 700 based 308 (11.25" twist) will handle 45 grs. of Varget with a 175. The 1-10" AIAT gives best results with 44.7 grs.
All my 8208 data is buried in a moving crate somewhere.
All my 8208 data is buried in a moving crate somewhere.
I tried 44.8 grs. and started getting a little sticky bolt lift. 44.7 gives good velocity and an 6.9 SD, bolt opens with ease. Also with 44.8 the SD opened up to 10.9.
Amazing what a tenth of powder will do.
I have used IMR4064 for a long time. Always had pretty good results. I use 175 noslers, sierras, and 178 hornadys. All work just fine in my gun.
I like and have had great results in my A5 and SR25 with both bullets using the following:
1) IMR4064
2) RE15 - temp sensitive but can achieve stupidly precise groups and very low SDs
3) Varget
Use a 210M primer if working with Federal commercial brass “Fed 308 Win” headstamp. I have found Remington 9 1/2 primers are a good combo if working with Lake City LR stamped brass.
Start the jump at .030 and work you way in or out at .010 increments until you find the sweet spot for your rifle and load recipe.
There are so many good choices that its hard to recommend one. But my favorites are 4064 and Varget.
I haven't found that sweet spot yet. What kind of case were you putting 45GRS of varget in and seating a bullet? I shot 44GRS of varget in Lapua brass and it was full. It also was running 2805 FPS and loosening up primer pockets. That's out of a 24" Brux 11.25 twist barrel. I know every barrel is different.
Not wanting to speak for him but He may have a non-sammi chamber....PTG’s 308 Win tactical match reamer allows me to run 45.3g Varget and a 9 1/2 primer with no visible pressure signs (case does expand by .0015 just above the extractor grove so I know I’m knocking on the door at pressure. I have a 12 twist.
2754-2769 across 3 shots a couple weeks ago w/175 smk; im going to load it again (5 rounds) and shoot it this weekend. Assuming I don’t see any troubling pressure indicators with the first shots, I’ll shoot all five rounds. For this load I will be using Black Hills brass and Rem 9 1/2 LRP and jump .030. Will follow up here with results and let you know if it’s worth pursuing or not. I will also be testing charges of 43.5, 44, 44.5 (varget).
barrel is a Schneider 6-grove at 26” (25” when measured from the lug).
Out of about 8 different powders I used in my .308 for 168 and 175 SMK's I've found 3 that work, what I'd call, "the best" of them. These are: Varget, H4895 and AR-Comp. While the SMK's can do just fine with long jumps, I get good results with .010 - .020.
Varget, because of it's popularity and well recommended, was one I went to first and upon getting excellent results with it I was slow to try anything else. It performs really well in my .308 and the only real negative I might point to is that is tends to burn kinda dirty.
When I eventually got around to trying H4895, I found I liked it better than Varget as performance was just good with a little more velocity and I was able to load more consistent loads for some reason. I was getting consistent single digit SD's and low ES around 20 fps.
Then, AR-Comp came along and I was a little skeptical at what it might do in my .308. But I found it performed as well as the H4895 and was giving me about the same MV. So, I've been shooting a lot of it these days and can say I like it over Varget. And, it's just about as temperature stable. The one outstanding feature with this is no copper fowling and not much in carbon deposit like one will get with Varget. Also, it seems to be a lot easier on lands as I notices that my lands doesn't move as fast as it did with Varget.
For a .308, I just do think anyone can go wrong with either of these three powders.
Lapua, 175 seated .2 off full length Accurate Mag magazine without the front plate. Couldn't tell if the chamber was oversize or not but is is a slightly compressed load. 700 action was trued up many years by Darrell Holland and has many 1,000's of rounds through it. The only pressure sign it shows is flattened primers. Bolt lift is like butter.
Anybody load subsonic 308 using something other than trailboss? I've been using 175 smk's with 10 gr of TB but was wondering if there are other powder options
I got 46gr of IMR4064 in a jageman case with 175gr nosler CCs, I think my CBTO was 2.28??? I can't remember offhand, I'll have to look in my notes. It didnt show any pressure and it wasn't a hard lift. But the primer pockets were noticeably looser compared to the other ones. I was just trying to see what the limit of my setup was. The primers were a little flat, but nothing I would worry about. I definitely wont do it anymore though. I basically burned 10 cases on it that will have looser pockets now. I have a howa factory barreled action
I'm not competing and I've grown tired of hand weighing each charge so I tweaked my set up some. I have switched to ball powders for my reloading, for .308 I have gone to AA2520. I stopped reloading 5.56 but when I did it 2520 worked great. People talk about it being unstable and I am sure it is but I didn't notice it in the conditions that I shot in. It used to take me an hour to load 100 rounds of ammo now I can do it in about 20 minutes.
Have you ever tried Alliant's Pro 2000MR? A couple years back I tried a pound of it and the load I came up with for my gun performed really well (like with 49.0 grs) . . . as long as the ambient temperature remained within a narrow margin. If found it to be particularly sensitive to the Arizona summer heat. With the range of temps here an using ball powers here, I've have to develop load for various temp ranges and then keep a close eye on ambient temps.
I haven't had my 308 long, but I use unique in 54r, x39, 300 sav, 06 with lead and jacketed bullets.
IMR4064 behind a 185 juggernaut 2.815 coal currently.
Next will be getting my hand on some 2000 MR for the jugs. Concerned about temp stability tho
Next will be getting my hand on some 2000 MR for the jugs. Concerned about temp stability tho
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